RNA processing in the male germline: Mechanisms and implications for fertility

Mammalian spermatogenesis is a tightly coordinated process that gives rise to mature spermatozoa capable of fertilising an ovum during sexual reproduction. A population of stem and progenitor cells known as undifferentiated spermatogonia enables continual spermatogenesis throughout life. A complex transcriptional network that balances self-renewal of spermatogonia with their timely differentiation in order to maintain constant fertility regulates this process. Importantly, post-transcriptional regulation of gene expression plays a critical role in spermatogenesis, necessitated by the profound genetic and morphological changes that occur during meiosis and sperm maturation. Pre-mRNA splicing, mRNA export, maintenance of transcript stability and translation are key RNA processing steps that are regulated in the male germline to maintain coordinated gene expression. In this review, we examine these processes in the context of mammalian spermatogenesis and provide an overview of key mediators at each step.